1. Field of the Invention
The present invention relates to a liquid ejection head, a liquid ejection apparatus and an abnormality detection method for a liquid ejection head, and more particularly, to a structure of a liquid ejection head and detection technology for detecting a mechanical abnormality, such as cracking or deformation, of a nozzle plate.
2. Description of the Related Art
In recent years, there have been demands for high-resolution image formation in inkjet recording apparatuses. In order to achieve this requirement, semiconductor processing technique is employed for forming nozzle apertures, through which ink droplets are ejected, in a nozzle plate made of silicon, for example, and the nozzle apertures are processed with higher definition and are arranged at higher density in the nozzle plate.
However, in general, silicon plates are liable to crack upon receiving external impacts or stresses. If the nozzle plate cracks, then ink leakage is liable to occur from the flow channels and liquid chambers arranged on the opposite side of the ink ejection surface.
On the other hand, metal plates and resin plates are liable to be deformed upon receiving external impacts or stresses. If the nozzle plate is deformed, deformation of the nozzle apertures and variation in the orientations of the nozzle apertures, and the like, occur and affect the ink ejection characteristics.
U.S. Pat. No. 7,347,532 to Chen et al. relates to technology for forming nozzle apertures by means of semiconductor processing technique on silicon nozzle plates, but is silent about the problem of cracking of the silicon nozzle plates and mechanical abnormalities in the resin nozzle plate or metal nozzle plate.